Process for development of photographic silver halide color materials



United States Patent Oflice 3,512,979 Patented May 19, 1970 3,512,979PROCESS FOR DEVELOPMENT OF PHO- TOGRAPHIC SILVER HALIDE COLOR MATERIALSTadashi Nagae, Haruhiko Iwano, and Isao Shimamura, Kanagawa, Japan,assignors to Fuji Photo Film (30., Ltd., Kanagawa, Japan No Drawing.Filed June 14, 1967, Ser. No. 645,900 Claims priority, applicationJapan, June 17, 1966, 41/39,231 Int. Cl. G03c 7/30 US. C]. 9655 6 ClaimsABSTRACT OF THE DISCLOSURE In the case of developing a photographicsilver halide light-sensitive color film in a developer containingpphenylenediamine or a derivative of it, the formation of fogs can bereduced without lowering the developed color density by incorporating inthe developer a mercapto aliphatic acid or derivative thereofrepresented by the formula: HSRCOOM, wherein R is a divalent alkyl grouphaving from 1 to carbon atoms, inclusive, in the chain, M isH, or analkali metal, or a monovalent positive group such as NHJ. Preferablyused in coupler developer solutions.

BACKGROUND OF THE INVENTION Field of the invention The present inventionrelates to an improved process for color development of photographicsilver halide color materials and, more particularly, to a process forcolor development using a color developer containing a mercaptoaliphatic acid or a derivative thereof.

Description of the prior art A multi-layer photographic material usedfor color photography has usually on a support at least threesuperimposed silver halide layers having different spectralsensitivities. For example, such photographic color material is usuallycomposed of a lowermost red sensitive emulsion layer, a green sensitiveemulsion layer, a yellow filter layer and an uppermost blue sensitiveemulsion layer, in that order. By the yellow filter layer, a blue lightpassed through the uppermost blue sensitive emulsion layer is absorbedalmost completely, so that it does not affect the green sensitive or thered sensitive emulsion layers. Further, in some cases, the material mayhave other emulsion layers or intermediate layers for other specificpurposes, and may have also a surface protective layer. On the otherhand, in the case of color positive film or paper, the yellow filterlayer is omitted and the arrangement of the silver halide emulsionlayers on the support may often be changed to suit the circumstances.

In the usual reversal photographic color process, a color image isobtained by subjecting the aforesaid photographic color material, afterexposure, to (l) a first development, (2) washing, (3) reversal exposure(to red light), (4) cyan development, (5) wash, (6) reversal exposure(to blue light), (7) yellow development, (8) wash, (9) second black andwhite development, (10) wash, (l1) reversal exposure (to white light),(12) magenta development, (13) Wash, (14) bleaching, (15) Wash, (16)fixing and (17) final wash.

In the color developments in the above-mentioned processes, a colordeveloper mainly consisting of p-phenylenediamine or a derivativethereof is usually used. In such a color developer, anti-foggants, suchas, 6-nitro-benzimidazole, are usually incorporated to prevent theformation of fogs, but the addition of the anti-foggant is accompaniedwith the disadvantage of reduction in developed density, or that ofincrease in developing time necessary to obtain sufiicient density. Theprolonged development causes a color contamination. Recently, variousantifoggants have been reported which do not reduce the density so much,for example, formamidinothiomethyl compounds (U.S. Pats. 2,899,306,British Pat. 886,722) and tetrazaindenyl or pentazaindenyl compounds(Birtish Pat. 898,005 and US. Pat. 2,956,876).

'lherefore, an object of this invention is to provide a colordevelopment process capable of preventing effectively unexposed areas ofa photographic silver halide color material from being fogged duringdevelopment, preventing the reduction in developed color density,reducing remarkably the formation of color contamination, promoting therate of bleaching, and increasing color purity.

SUMMARY OF THE INVENTION The inventors have found, as the results ofvarious investigations, that the above objects of this invention can beachieved by incorporating in a color developer mainly consisting ofp-phenylenediamine or a derivative thereof a mercapto aliphatic acid ora derivative thereof represented by the following general formula:HSRCOOM, wherein R represents a divalent alkyl group having from 1 to 5carbon atoms, inclusive, in the chain, M is H, or an alkali metal, or amonovalent positive group such as NH4+- The examples of the compoundsshown by the above general formula are illustrated below:

(1) Thioglycollic acid HS--CH COOH (2) a-Mercaptopropionic acid SH (3)fl-Mercaptopropionic acid HS(CH COOH (4) p-Mercaptobutyric acidCHaOHOHz-C 0 OH in (5) B-Mercaptoisovaleric acid O-CH2-C 0 OH 0113 SH(6) e-Mercaptocaproic acid HS-(CH COOH In the above formula, the numberof carbon atoms in R is from 1 to 5 but is most preferably from 1 to 3and the mercapto aliphatic acids having higher carbon atoms in R arecomparatively inferior on the point of solubility in the colordeveloper.

The above-mentioned compounds of this invention are effectively added tocolor developers for processing of photographic reversal color materialsand these compounds are particularly effective for the development bycoupler-developer type solutions, that is, the development composed ofthree different color developers into which couplers suitable for eachof them are added and used successively.

The concentration of the mercapto aliphatic acids or the derivativesthereof used in the present invention depends on compound to beemployed, type and concentration of color developing agents used, typeof coupler and the pH of the color developer. Usually it falls in therange from 0.00 to 2.0 g. and most preferably 0.01 g. to 0.5 g. per oneliter of the color developing solution. If

the concentration of the compound of this invention is too high,decrease in developed density occurs although the fog formation may besufliciently prevented, while if the concentration is lower than thatmentioned above, the anti-fogging effect will be insufficient.

A color developing solution may contain, besides a color developingagent and a color coupler, alkaline substances such as sodium hydroxideor sodium carbonate; fog retarders, such as potassium iodide, potassiumbromide, or benzimidazole, an anti-oxidant, such as sodium sulfite andother inorganic salts, such as sodium sulfate. The mercapto aliphaticacids or derivatives thereof used in this invention can be effectivelyadded to the color developer containing the aforesaid various additives.

In a photographic reversal color process in accordance with the presentinvention, any silver halide emulsion can be employed. This may besensitized by a chemical sen sitizer and the like. Besides, other usualstabilizers, hardening agents, etc., may also be used in the emulsion.

The color developing agents used in the color developers of thisinvention are N,N-diethyl-p-phenylenediamine sulfite,N,N-diethyl-3-methyl-p-phenylenediamine hydrochloride,4-amino-3-methyl-N-ethyl-N-methane-sulfonamide ethylam'line sulfate,4-amino-3-methyl-N-ethyl-N-hydroxyethylaniline sulfate,N-et-hyl-N-hydroxyethyl-p-phenylenediamine sulfate and the like.

Further, the examples of cyan couplers used in cyan developer of thisinvention are 2,4-dichloro-l-naphthol,2,-4-dichloro-S-teryl-sulfonamide-l -naphthol, 1 oxy 2-benzylnaphthamide, 2,6-dibromo-1,5-dihydroxynaphthalene and the like.Yellow couplers for yellow developers are benzoylacetoanilide,1-w-benzoyl-4-(p-toluene-sulfonamido) acetoanilide and the like andmagenta coupler for magenta developers are1-phenyl-3-(m-nitrobenzoylamino)-5-pyrazo1one, cyanoacetyl cumarone andthe like. Other couplers soluble in the developer may also be suitablefor this invention.

The following examples will serve to illustrate more fully the manner ofpracticing the invention.

EXAMPLE 1 A multi-layer color film prepared by applying on a celluloseacetate support a gelatino iodobromide emulsion sensitive to red light,a gelatino iodobromide emulsion sensitive to green light, a yellowfilter layer containing colloidal silver capable to absorb blue light,and a gelatino iodobromide emulsion sensitive to blue light, in thisorder successively, was exposed on a sensitometer and then subjected tothe following processes:

Tempera- Time Process Step ture 0.) (min.)

First development 24 5 Wash 24 2 Reversal exposure (to red light) (fromthe back), GMS- 200 Cyan color development 24 5 Wash 24 2 Reversalexposure (to blue light) (from the front), OMS 200 Yellow colordevelopment 24 5 ash 24 2 Second Black and White Development- 222 g asReversal exposure (to white light), OMS... 2, 000 Magenta colordevelopment 22: 5 8 24 2 24 2 Fixin 24 2 Final wash 24 2 Thecompositions of the processing solutions used in this process were asfollows:

First and second black and white developers Sodium sulfite g.N-methyl-p-aminophenol sulfate-2.0 g. Hydroquinone8.0 g.

Sodium carbonate mono-hydrate-S 2.5 g. Potassium bromide5.0 g.

Potassium thiocyanatel.0 g.

Water to make-1 liter Cyan developers Yellow developer Sodium sulfite5.0g.

N,N-diethyl-p-phenylenediamine sulfate-2.5 g. Potassium bromidel.0 g.

Potassium iodide (0.1% aqueous solution)5.0 ml.w-Benzoyl-4-(p-toluenesulfoamido) acetoanilide1.2 g. Sodium hydroxide2.5g.

Magenta color developer Sodium sulfite-S .0 g.

2-amino-5-diethylaminotoluene hydrochloride2.0 g. Potassium bromide-0.8g.

1-phenyl-3- (m-nitrobenzoylamino -5-pyrazolone1.4 g. Sodiumhydroxide-2.0 g.

n-Butylamine5.0 ml.

Water to make-l liter.

Ferricyanide bleach Potassium ferricyanide-IOO g. Potassium bromide10 g.Borax-2 g. Boric acidl g. Water to make1 liter.

Fixer Sodium thiosulfite-- g. Sodium sulfite--10 g. Water to make-1liter.

In this color reversal processing, the mercapto aliphatic acids of ourinvention were added to the cyan developer (the amount of mercaptoaliphatic acids added were described by grams per one liter of the colordeveloper throughout the examples of this invention).

Experiment No. Additives Amount, g./l.

1 Nona 2 B-Mercaptoproplouic acid 0. 05 3- do 0. 10

The photographic results obtained by the development are shown in thefollowing table in which the degree of color contamination of the areasexposed to red light is expressed by the ratio (DR/DG), that is theratio of red filter density to green filter density and the ratio(DR/DB), that is, the ratio of red filter density to blue filter densityof the areas exposed to red light. The lower these ratios are, thebetter the purity of the red color on a photographic material reproducedfrom an object.

Purity of Red Color Reproduced Experiment No. DR/DG DR/DB 5 As shown inthe above table, by incorporating the mercapto aliphatic acid of thisinvention into the color developer the quality of color reproduction wasimproved effectively.

EXAMPLE 2 In the process as described in Example. 1, after the cyandevelopment, the film was washed with water for 8 minutes and bleachedand fixed as in Example 1 to provide a cyan image.

The results are shown in the following table. In the table, the degreeof cyan color contamination is expressed by cyan density values ofthereas exposed to red light. The cyan density at the area is caused bythe formation of undesirable fogs in the green or blue sensitiveemulsion layers which should be principally developed to magenta oryellow.

A single layer film containing-no sensitizing dye was exposed to a whitelight instead of red reversal exposure and then developed in the cyandeveloper as in Example 1. Thereafter, omitting the blue reversalexposure, yellow color development and the second black and whitedevelopment, the film was subjected to the magenta color development andthen, after a wash of 8 minutes, was bleached and fixed. The results areshown in the following table in which the color density ratio DG/DR,that is, the ratio of the magenta density to the cyan density, shows theextent of another type of color contamination, that is, contamination incyan. A large value of the ratio means that the extent of magentacontamination in cyan during magenta color development is great. Theaddition of the compound of this invention lowers the contaminationvalue as shown in the following table.

Color Con- Experiment Additive to Cyan Color Amount tamination N 0.Developer (grams) D G/D R None 0. 49 fi-Mercaptopropionle aoid 05 0. 31

Sodium B-mercaptopropionate.-. 0. 12 0. 30

EXAMPLE 4 The photographic material of Example 1 was developed by thesame procedure as in Example 1 except that the compounds of theinvention are added to yellow developer The photographic results thusobtained by the developments are shown in the following table. In thetable, the purity of the blue color reproduced is shown by the ratioDB/DG, that is, the ratio of the blue filter density to green filterdensity and by the ratio DB/DR, that is, the ratio of blue filterdensity to red filter density of the areas exposed to a blue light. Thiscorresponds to the extent of purity of the reproduced color of a blueobject. The lower the ratio, the better the quality. The Stain D6 or DBin the table shows density values of the highest-light portion of thetest film measured through green or blue filters and the lower thevalue, the better the image quality. Besides these values, the maximumblue density (D and the maximum green density (D are also shown in thetable. Of course, the larger the value, the better the quality.

Purity of Blue Color lljllgp'eri- Reproduced Stain Maximum Density N0.DB/DG DB/DR DG DB DGmex. DBmeh' EXAMPLE} 5 A single layer spectrallyunsensitized photographic material was processed as in Example 1, butthis time, the compounds of this invention are added to the yellowdeveloper and the red reversal exposure, and the cyan color developmentwere omitted.

The results as shown in the following table, in which the ratio DG/ DB,that is, the ratio of the magenta density to the yellow density showsthe extent of color contamination. Inadequate yellow development causesmagenta 'color formation in the film, that is, magenta colorcontamination in yellow. By the addition of the compound of thisinvention, the value of color contamination was decreased effectively.

Color Contamination, D G/DB Amount (grams) Experiment No.

The photographic materials of Example 1 were developed by the sameprocedure as in Example 1, except that the cyan developer applied at 24C., for 7 minutes, has the following composition:

Cyan developer Purity of Red Color Reproduced Experiment I Amount N0.Additive (grams) D RID G D R/DB 1 None 0. 34 0. 36 2. Thioglyeollic acid0. 1 0.30 0. 31 3. B-Mercaptopropionie acid 0. 1 0. 28 0. 29 4-a-Mercaptopropionie acid- 0. 1 0. 29 0. 5. a-Mercaptocapronie acid- 0. 10. 31 0. 33

EXAMPLE 7 The same procedure as in Example 4 was repeated but using ayellow color developer, applied at 24 C., for 7 mints, having thefollowing composition:

Yellow developer Sodium sulfite5.0 g.

Sodium sulfate50 g.

Potassium bromide-O.5 g.

Potassium iodide (0.1% aqueous solution)10 ml. Benztriazole (1% methanolsolution)-1.0 ml. N,N-Diethyl-p-phenylenediamine sulfite3.0 g.w-Benzoyl-o-chloroacetonanilide-1.8 g.

Sodium hydroxide-2.8 g.

Water to make 1 liter.

The results obtained by adding the mercapto aliphatic acid of thisinvention into the yellow color developer are shown in the followingtable.

2. The process as claimed in claim 1 wherein said mercapto aliphaticacid is selected from the group consisting of thioglycollic acid, amercaptopropionic acid, 3 mercaptopropionic acid, ,8 mercaptobutyl icacid, ,8 mercaptoiso-valeric acid, and u-mercaptocapronic acid.

3. The process as claimed in claim 1 wherein said .rnercapto aliphaticacid and a derivative thereof are incorporated in the color developingsolutions in an amount of from about 0.001 g. to 2.0 g.

4. The process as claimed in claim 1 wherein said compound isincorporated in a cyan color developing solution.

5. The process as claimed in claim 1 wherein said compound isincorporated in a magenta color developing solution.

Purity of Blue Color Reproduced Stain Experiment Amount No. Additive(grams) DB [D G DB/D R D G DB ne 0. 40 0. 45 0. l4 0. l4

2 Thioglycollic acid 0. 1 0. 35 O. 43 0. 12 0. 11

3-- fl-Mercaptopropionic acid 0. 1 0. 30 0. 40 0. 10 0. 10

4.- a-Mercaptopropionie acid- 0. 1 0. 32 0. 41 0. 10 0. 10

5 e-Mercaptocapronic acid- 0. 1 0. 34 0. 42 0. 11 0. 11

What we claim is: 25 6. The process as claimed in claim 1 wherein saidcom- 1. A process for color development of a photographic silver halidecolor material comprising contacting said material with a.color-developing solution containing a color developing agent selectedfrom the group consisting of pphenylenediamine and derivatives thereof,a coupler soluble in the developing solution, and a mercapto aliphaticacid compound represented by the following general formula: HSRCOOM,wherein R represents a divalent alkyl radical having from one to fivecarbon atoms and M represents a member selected from the groupconsisting of hydrogen, alkali metal and an NH radical.

pound is incorporated in a yellow color developing solution.

References Cited UNITED STATES PATENTS 3,201,243 8/1965 Larson 96-1093,255,008 6/1966 Telft. 3,326,684 6/1967 Nishio 96--61 J. TRAVIS BROWN,Primary Examiner U.S. Cl. X.R.

